Hello All,

Last week, I had a wheel bearing fail on me driving to work. I had it towed to Mavis, where they replaced the bearing. I also had 2 replacement cats, which I had them put on plus all 4 O2 sensors as well. This is where the fun begins.

Now, whenever I start the car, it starts fine, and drives perfectly for 20-30 seconds. Then the car loses all power, and will stall if you push the clutch in. But you turn the key to the off position, then start it, it starts right up, and drives perfectly for 20-30 seconds again! I am not throwing any codes (besides for a misfire, which is a symptom, not a cause), and I am positive that the O2 sensors are in the right spot. The car was running fine before I got the work done. I even took it to Audi to check it out, and they said the Bank 2 Sensor 1 was possibly bad out-of-the-box, because it was giving a low value and richening the A/F mixture. They replaced it, and it does the same thing! I even unplugged all 4 sensors, and the car still runs exactly the same way. I would think if a cat was plugged, then it wouldn't even run right for 30 seconds. This feels as though when you start it, the engine computer does its checks, then after 20-30 seconds it starts reading the sensors, and thinks I'm running lean for some reason.

Mavis did zip-tie some O2 wires to my valve cover breathers, and broke both of the hoses. I thought this was it, because if there is extra air coming in from after the MAF, then the car will run lean, which the computer will try to compensate for by richening the mixture, correct? I plugged both hoses going into the TB with a urethane cap, but it didn't help at all.

Also, is it possible that my MAF is going bad? I am not rev-limited even when the engine bogs down, so I didnt think it was that.

Does anyone know the proper voltage range that is supposed to come out of the MAF at idle so I can check it? I am going to check the resistance of the IAT thermistor as well.

I would really appreciate any help from anyone here with more in-depth knowledge than I have. I feel like this is going to be something stupid, and I cant prove that it was running right before I brought it in (it was flat-bedded).

Sorry for the book!

-Brian